The vfs_getvfs() function returns
the mount point structure for a file system given its file system
identifier. The file system ID should have been allocated by
calling vfs_getnewfsid(9); otherwise, it will not be found.

A major user of
vfs_getvfs() is NFS, which uses the fsid as part of
file handles in order to determine the file system a given RPC is
for. If vfs_getvfs() fails to find the mount point related
to fsid, the file system is considered stale.

RETURN VALUES

If fsid is found, the mount point
for the ID is returned; otherwise, NULL is returned.